Relativistic Meson Spectroscopy and In-Medium Effects

We extend our earlier model of $q\bar q$ mesons using relativistic quasipotential (QP) wave equations to include open-flavor states and running quark-gluon coupling effects. Global fits to meson spectra are achieved with rms deviations from experiment of 43-50 MeV. We examine in-medium effects through their influence on the confining interaction and predict the confining strength at which the masses of certain mesons fall below the threshold of their dominant decay channel.Comment: 12 Pages, 2 Postscript figures (appended at the end with instructions, available also from [email protected]

USDOT at 50: The Early Years: Compiled for the 50th Anniversary, April 1, 2017

The essays and recollections appearing here have been assembled in the History Committee of the Transportation Research Board and will be housed in the US DOT's National Transportation Library on the occasion of the 50th anniversary of the opening of the US Department of Transportation. The opening document consists of excerpts from A Great Honor, the memoir of DOT's first Secretary of Transportation, Alan S. Boyd, with his permission. The remaining pieces were prepared by some of those who were at DOT at the beginning, many of whom had leadership positions in significant areas that established the early policies and directions of the agency. It does not aim to be a comprehensive or exhaustive history, but rather seeks to set down for future reference notable events and decisions, some very momentous, some more light-hearted, deemed worth preserving in the eyes of those who were there. No attempt has been made to design, organize, or otherwise modify the thoughts of the preparers. These are their thoughts in their words. You will find some very skilled writers here addressing some very important events in transportation history, and many authors who went on to brilliant careers beyond their early DOT days. It is a tribute to the amazing collection of people assembled there in the formative years of the agency. This commemoration of the 50th anniversary of the opening of DOT has been marred by the death last night of William T. Coleman our fourth Secretary, whom we all remember with great fondness and respect. Several pieces, prepared over the past year refer to his role in the Department's early days. His very distinguished tenure as Secretary is overshadowed by his immense influence in American History. Thus, with his loss, of the first four Secretaries who served in the formative early years of DOT, only Secretary Boyd remains. It is notable that the tenure of those first four; Boyd, Volpe, Brinegar and Coleman encompassed the first ten years of the Department's history from January 1967 to January 1977. These documents focus on that first 10 years, the critical period in which the Department's culture formed. It is the most distant period and therefore the most important to preserve. This collection is dedicated to Secretary Boyd, his successors and to the great agency they set on its path

A Two-Dimensional Model with Chiral Condensates and Cooper Pairs Having QCD-like Phase Structure

We describe how a generalization of the original Gross-Neveu model from U(N) to O(N) flavor symmetry leads to the appearance of a pairing condensate at high density, in agreement with the conjectured phenomenon of color superconductivity in $(3+1)$-dimensional QCD. Moreover, the model displays a rich phase structure which closely resembles the one expected in two-flavor QCD.Comment: 11 pages, 1 fugure, Presented at TMU-Yale Symposium on Dynamics of Gauge Fields: An External Activity of APCTP, Tokyo, Japan, 13-15 Dec 199

Inside the metropolis: the articulation of Spanish metropolitan areas into local labor markets

In this article, we delimit local labor markets (LLMs) in order to analyze the internal structure and organization of Spanish metropolitan areas. LLMs are defined as self-contained and cohesive areas in terms of commuting flows. Unlike the conventional approach to polycentrism based on the analysis of commuting flows that begins with the identification of subcenters, our analytical strategy does assume any a priori structure and is compatible with the relationship between places of work and residence having other locational and spatial organization patterns. The analysis is performed at three different scales of detail linked to three self-containment levels for the LLMs delimited and three population groups (total, males, and females). The results show that metropolitan areas are complex, fuzzy, multidimensional spaces, where the conditions of spatial organization are manifested in different ways depending on the parameters and variables used.This work was supported by the Spanish Ministry of Economy and Competitiveness [grant numbers CSO2011-29943-C03-01, CSO2011-29943-C03-02, CSO2014-55780-C3-1-P, and CSO2014-55780-C3-2-P (National R&D&I Plan)]

Wolff-Type Embedding Algorithms for General Nonlinear σ\sigma-Models

We study a class of Monte Carlo algorithms for the nonlinear $\sigma$-model, based on a Wolff-type embedding of Ising spins into the target manifold $M$. We argue heuristically that, at least for an asymptotically free model, such an algorithm can have dynamic critical exponent $z \ll 2$ only if the embedding is based on an (involutive) isometry of $M$ whose fixed-point manifold has codimension 1. Such an isometry exists only if the manifold is a discrete quotient of a product of spheres. Numerical simulations of the idealized codimension-2 algorithm for the two-dimensional $O(4)$-symmetric $\sigma$-model yield $z_{int,{\cal M}^2} = 1.5 \pm 0.5$ (subjective 68\% confidence interval), in agreement with our heuristic argument.Comment: 70 pages, 7 postscript figure

Commuting in America III: The Third National Report on Commuting Patterns and Trends

TRB has released the third edition of Commuting in America. The report was prepared by author Alan E. Pisarski under a joint project of the National Cooperative Highway Research Program (NCHRP) and the Transit Cooperative Research Program (TCRP). Commuting in America III is one of the most comprehensive documents of its kind. Based on the latest census information available, it contains 155 figures, 79 tables, and some 100 “factlets” that tell the story of America’s commuting trends and patterns over the last ten years. This publication will be a valuable reference for the transportation community—practitioners, researchers, and decision makers—who wish to understand how individual behavior and public policies have affected, and will continue to affect, commuting patterns. A press release and factsheets on information contained in Commuting in America III is also available

Summary and Recommendations of the Workshop on National Urban Congestion Monitoring

This document reports on a 2 1/2-day workshop convened at U.S. DOT from May 30 to June 1, 1990. It is intended to summarize the discussion, and to present the general findings and overall recommendations of the workshop rather than exhaustively report on the detailed proceedings of the sessions. A list of workshop participants is contained in Appendix A